This invention relates generally to electrical apparatus, and more particularly to a circuit breaker having a chemical operating mechanism with interchangeable, variable elements used to vary the performance characteristics of the breaker.
The use of chemical energy as a mechanism stored energy source has great potential for the operation of a wide variety of switching devices. Switching devices such as high speed grounding switches, current limiters, special purpose high speed closing switched for bypassing capacitors or reactor insertion and power circuit breakers present a wide range of energy levels. Future needs for these devices indicate energy requirements and operating times exceeding present available mechanism capabilities and which could be satisifed with chemical energy mechanisms.
Recent advances in power circuit breakers, and particularly the increasing use of commonly-referred to puffer-type circuit breakers, have resulted in increased demands on mechanism performance. Puffer circuit breakers require high energy levels because of the high moving masses and gas pressure forces required for interruption. The need for two cycle operating times, higher interrupting current and the move to higher voltage per break has further increased energy levels and demands for faster operations. Because of stored energy capability and the extremely short time for initiating the release of the stored energy, chemical energy devices are being looked upon increasingly favorably for application to the operation of puffer circuit breakers.
From a manufacturing standpoint, however, it is desirable to standardize as much as possible the various components used in manufacturing the wide range of circuit breakers which, for example, may include voltage ratings of from 121 KV through 800 KV with interrupting current capabilities of 40 and 50 KA. This desire for standardization and minimization of components is likewise desirable in the manufacture of the operating mechanism used for causing the separation of the main contacts of the circuit breaker. The provision of a low cost mechanism family for switching devices which utilizes only a small number of standard, interchangeable parts that can be produced in quantity, and which can give a varying energy range of a factor of, for example, 100 between the highest and lowest energies available, is desired.